


All Good Things...

by Writer_Geekgirl



Series: Castiel and Dean: An AU Love Story [29]
Category: Supernatural
Genre: Alternate Reality, Alternate Universe - Canon Divergence, Alternate Universe - Star Trek Fusion, Archangel Gabriel (Supernatural), Episode: s01e27 The Alternative Factor, Episode: s02e10 Mirror Mirror, Fluff and Angst, M/M
Language: English
Status: Completed
Published: 2018-10-30
Updated: 2018-10-30
Packaged: 2019-08-09 20:53:14
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,686
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16457030
Author URL: https://archiveofourown.org/users/Writer_Geekgirl/pseuds/Writer_Geekgirl
Summary: In the ongoing series in which the Winchesters visit alternate realities, Dean, Castiel, and Sam find themselves on the Starship Enterprise. With the aid of Kirk and Spock, they finally figure out how to deal with the parallel universes and to send everybody home.This work is part of the Destiel Promptober in which there is a different AU theme for each day in October. The AU for the day is Star Trek.





	All Good Things...

**Author's Note:**

> This story is a bit on the nerdy side and mentions two Star Trek episodes that involve parallel universes. You don't have to watch them to understand the story, but they are kinda cool.

Dean looked around the room in amazement. He seriously was on the Starship Enterprise with Castiel and Sam. Captain James Kirk stood in front of him with a phaser drawn. Dean smiled cheekily and said, "My name is Dean Winchester, I'm an Aquarius, I like frisky angels, and I fight monsters. I'm trying to save the multiverse. Want to help me?”

Kirk hit a button on the wall and said, "Mr. Spock, can you come to my quarters?"

Spock's voice came over the intercom, "Yes, Captain."

Dean knelt down next to the still unconscious Sam and shook him gently. "Wake up, Sam."

Sam groaned, "Did we stop him, Dean?"

"Nope, he got away and you aren't going to believe where we are."

Sam sat up groggily and looked around. When he saw Kirk, he stared at him in awe. "Are we actually on the Enterprise?"

"Seems so," Dean answered smugly.

Kirk watched them without saying anything else until Spock entered the room. Spock said, "Who are these people, Captain?" He looked at the trio curiously.

"Tell me again who you are," Kirk asked.

Castiel responded, "I am Castiel, an Angel of the Lord. My companions are Dean and Sam Winchester. We are in search of a Sam from an alternate reality who is disrupting the fabric of space and time. We are afraid that he might cause catastrophic damage to the multiverse."

Spock raised an eyebrow, "They are here from another reality, Captain?"

Kirk put away his phaser. "It appears so, Spock."

Dean said, "It's like that _Mirror Mirror_ episode where Spock has a beard in a parallel universe or _The Alternative Factor_ where Lazarus came from another parallel universe."

Spock raised an eyebrow at Dean, "How do you know these details?"

Dean responded, "In our reality, you're a television show. I've seen every episode at least a dozen times. It's weird, but Sam and I once crossed into an alternate universe where we were actors in a television series based on our actual lives."

Kirk looked at them dubiously. Spock said, "May I remind you, sir, of the time in which you, Dr. McCoy, Mr. Scott, and Lt. Uhura switched places with your counterparts at Halkan because of a transporter error during the magnetic ion storm. Or when Lazarus passed through the corridor between parallel universes and almost caused the destruction of both because he tried to confront the alternate version of himself."

Kirk nodded, "Because the matter and antimatter of two objects cannot occupy the same space at the same time."

"Correct, sir."

Dean's eyes widened, "So, when we confronted Sam, while this Sam was with us…"

Spock responded, "You could have caused a hole between parallel realities and matter from each could interact with the other, destroying both. Usually, there's a safety corridor between the two so this should not occur."

Castiel said, "That did not happen when I encountered an alternate version of myself other universes." 

Spock answered, "You do not feel human. Do, you mind if I scan you with my tricorder?"

Castiel tilted his head at Spock. Dean said, "It's ok, Cas. It's like an x-ray." 

Castiel responded, "Go ahead."

Spock scanned Castiel's body. His eyebrow arched, "Interesting, Captain. This being is not made of matter or antimatter but an undiscovered source of energy in a wavelength I have not seen before. It could be that his energy would not react the same way as the forms of energy found in our own and parallel universes would."

"He's an angel. That's his grace," Sam supplied. "He's in a vessel, but his true form is something else. A wavelength of celestial intent."

"Fascinating," Spock said. "I would like to do further scans…"

Dean interrupted, "He's my partner, not a lab experiment."

Sam blinked at Dean's choice of terminology but didn't say anything. Dean said, "Our souls have been traveling to parallel worlds and inhabiting versions of ourselves there. Why wouldn't that cause the destruction of the universes?"

Castiel said, "Because, like grace, the energy of the soul is neither matter nor antimatter."

Sam asked carefully, "So, you mean, that if any of us who had had counterparts in the alternate universe besides you ran into ourselves…"

"Would have annihilated both ours and the alternate reality, Sam," Castiel responded. "If the premise provided by Mr. Spock is correct."

Dean asked, "So we are still here by the random crazy happenstance the people who came over from the alternate universe are dead on our side, and the people we sent over there didn't exist on their side?"

Castiel said, "Basically, yes. I would think that my vessel would trigger a similar reaction even if my grace didn't; however, neither Castiel we met had been rebuilt by the ancient cosmic entity in the Empty. So, in effect, although my vessel is identical in appearance, it is not identical at the subatomic particle level."

Kirk paced the floor, "So, bottom line it for me, Spock. What do we need to do?"

"We need to find the alternate version of Sam and send him back to the universe he came from while keeping this Sam someplace where their matter will not interact," Spock answered.

"So, we need to stash Sam in sickbay or something?" Dean looked between Spock and Castiel.

Castiel said, "Dean, it might not be that easy. The Temple had some ancient energy around it that I believe may have contributed to both Sams being closer to each other than normally allowed without annihilation."

Dean looked dumbfounded, "We didn't explode two universes because of the Force? That is both terrifying and exciting."

A rustle of wings was heard right before Gabriel popped in the middle of the room. "Whoa, weird. How are we coming on the whole Sam crazy train, Dean-o? I tell you, that last place was a close shave on the not ripping holes in realities thing. Is that Spock and Captain Kirk? Awesome. Not Deep Space Nine awesome, but still awesome."

Kirk drew his phaser, while Spock went for his tricorder. 

Dean said to Kirk, "Don't bother. He's an archangel. I doubt that would make a dent."

Spock stared at his tricorder, "He is also composed of an unknown type of matter, similar to Castiel's, but exponentially more powerful."

"Archangel juice. What can I say?" Gabriel winked at Castiel. "I keep thinking one of these days Dad is going to bring Cas back as a real boy, but he is still just a seraph." He smiled sadly at Castiel.

Dean growled, "And you're an assbutt, Gabriel."

Gabriel smirked, "Witty, Dean, witty."

Kirk exploded, "Okay, everyone be quiet while we figure out what the hell we are going to do to fix this problem. I cannot allow any of you to destroy this universe."

Dean said, "Chill, Cap. We're trying to save it. We just almost accidentally destroyed it."

Spock walked over to the computer kiosk in Kirk's room. He said, "Computer, can you tell me if any temporal or magnetic rifts can be detected in this quadrant in the last 24 hours?"

The computer replied, "Affirmative. There have been two. One within the Captain's quarters and one on the planet Rigel IV, .76 light years away."

Spock looked at Kirk, "Captain, I assume that would be where the other version of Sam is."

"And what should we do?" Kirk asked.

Gabriel piped up, "If you can hold him still, I can send him back to his reality. I just have to get up close and personal."

Dean asked Gabriel, "Can you send my Sam safely home?"

Sam said, "Dean!"

Gabriel put his hand on Sam's arm, and Sam disappeared. He announced, "One probably very pissed off Sam sent back to the bunker on your world."

Castiel said dryly, "Better to piss him off than destroy the universes."

Spock met Kirk's eyes, "Captain, may I suggest that we travel as fast as possible to Rigel IV to send the other Sam back to his own universe? Moving through realities in the fashion in which he is doing is statistically likely to eventually end badly."

Kirk nodded, "Maybe it wouldn't be our universe, but in the next universe he travels too." Kirk touched the intercom button, "Sulu, could you please lay a course for Rigel IV. Would you gentlemen like to accompany me to the bridge?"

Dean's eyes lit up, "That would be awesome." He looked at Gabriel, "Behave."

"No tribbles in overhead bins," Gabriel whined.

Kirk stopped and looked at Gabriel stunned.

Gabriel conceded, "I'll behave."

The group went up to the bridge. Although the crew looked at them curiously, Kirk merely introduced them as visitors. As they hit warp speed, Dean whispered to Castiel, "So much cooler effects in Star Wars." 

Castiel muttered, "Dean, they were over a decade apart, and Lucas upgraded the special effects periodically."

The ship slowed down to sub-light speeds as it entered the Rigel solar system. 

Spock said looking at the equipment, "I am scanning the planet for him now, Captain." After a brief pause, he said, "I have located him, Captain, and sent his coordinates to the transporter room."

Kirk stood up, "Spock with me. Sulu, you have the con." Kirk walked to the elevator and the others followed. 

Dean looked nervously at Gabriel and Castiel. He whispered, "Will it be safe? I mean don't they disassemble my atoms and remake them. Will me still be me?"

Castiel raised an eyebrow at Dean, "What do you think happens when an angel flies you someplace? We become a wavelength that re-solidifies at the end of the journey."

"Comforting to know," Dean snorted.

In the transporter room, Kirk said to the transporter officer, "Five to beam down."

Dean felt both excitement and trepidation at getting on the transporter pad. He reached out and squeezed Castiel's hand for a moment. He tried not to think of the Star Trek movie where the crew member got transported inside the floor of a ship; however, soon as he remembered not to think about it, it became the only thing he could think about. He felt strange as he dematerialized, not too unlike he felt during the reality shifts.

They rematerialized in a room, where Sam was sitting tired on a couch. He stood up and said, "Dean." He advanced to Dean and pulled him into a hug.

Dean smiled at him weakly, "Hey Sam, long time, no see."

"I can't believe I found you; I've been looking for so long."

Dean looked over at Spock and Kirk and nodded at them. Kirk and Spock stepped out of the room into a hallway to give them privacy.

Dean said, "Let's sit down, Sam."

After the four of them were seated, Sam started, "I wasn't sure I'd ever find you and Cas again."

Dean couldn't meet Sam's eyes. He took a deep breath and said, "You still haven't, Sam."

Sam flashed a look of betrayal. He said, "Cas?"

"We're not your version of Castiel and Dean, Sam. We're from an alternate reality where our Sam is currently stewing in the bunker."

Sam looked at Gabriel. Gabriel said, "They're telling the truth, tiger. I'm sorry."

Sam replied with his shoulders squared, "I'll keep looking then."

Dean put an arm around Sam, "You can't, Sam. You're not supposed to breach the walls of realities this way. It's a miracle that something catastrophic hasn't already happened."

Castiel added, "It's too dangerous, Sam. If you were ever to get too close to one of the other Sams, your energies would have a polarizing reaction and cause the realities to bleed into one another and cause mass destruction."

Sam said, "But…"

"No, Sam. It sucks. It all sucks. But, you have to give it up," Dean's voice cracked, a single tear rolling down his cheek.

Gabriel smiled at him sadly, "You'll have me, Sammy. You'll always have me. I'll keep looking for a safer way to find our wayward brothers." Gabriel reached out and touched Sam's forehead. A thin tendril of blue grace flitted from Sam to Gabriel.

Sam said, "Would you be able to stop looking if I went missing, Dean?"

"Once upon a time, I would have said no, Sam. But, I've seen so much. So many iterations of us. I can't imagine endangering them all. Although we almost destroyed the universes, I saw so much good while traveling on this crazy ride. I've seen a couple of versions of you who had an apple-pie life with Jess, another where you were about to marry Eileen. I've seen some universes where Cas or I had kids. We can't take away their happy endings to give ourselves one."

Sam protested, "You have yours. You have Cas and your version of Sam. I don't have anything." Gabriel's face flashed a pained expression for a moment before relaxing his features.

Dean said, "Yeah, I'm lucky. But, I also know there's a Castiel out there that I let down and who is fighting Lucifer with just Chuck at his side. I put a Castiel on a bus heading out of town where he will never have a life with that Dean. Another one, where I had to kill Castiel myself to put him out of his misery. There are so many people out there, Sam. Places where our Charlie is alive. Where Mom and Dad didn't die."

Sam buried his face in his hands with his shoulders shaking. Gabriel put his arms around him. Dean could swear he also felt the swish of Gabriel's wings. He looked at the lack of personal space between them and stared at Castiel. Castiel gave a small shrug.

Gabriel said, "Say your goodbyes to the Star Trek guys, and I'll send you home."

Castiel and Dean walked into the hallway where Kirk and Spock were standing close together whispering. Dean again noticed the lack of personal space and gave Castiel an odd look. Castiel gave another small shrug.

Dean said, "We got everything sorted out. Gabriel can send everybody home."

Kirk responded with a smile, "Thank you for not destroying the universe. What about Sam?"

"It's going to suck for him, but there's not much I can do about it. If I went with him, my Sam would be hurt. I can't win. No way for me to defeat this Kobayashi Maru scenario."

Kirk looked startled a moment before smiling. Spock said, "Peace and long life."

Dean responded, "Live long and prosper, Spock."

Castiel added, "Dif-tor heh smusma."

Dean looked at Castiel quizzically. Castiel protested, "What? I speak Vulcan."

Dean muttered, "Such a nerd." The two of them returned to the room. Sam had regained his composure and was standing next to Gabriel.

Dean pulled Sam into a hug. "Sam, I know one thing. Wherever your Cas and Dean are, they are fighting with everything they have to get back to you. I have faith, every faith, that they will succeed."

Castiel hugged Sam. He looked at Gabriel, "You take good care of him."

Gabriel nodded, "Goodbye, little brother." He placed one hand each on Dean and Castiel.

A moment later, the two of them were in the bunker. Sam stared at them with obvious relief. Dean said, "We're safely home, Sammy. And hopefully, that will be the last reality shift ever."

Castiel looked forlorn, "I wish we could have found his Castiel and Dean."

Dean asked confused, "Cas, how come I could talk to myself in the endverse?”

"Zachariah never actually sent you to the future; he just played out a possible future for you in a green room."

"Huh, That smarmy bastard." Dean responded. "Well, anyway, we have a retirement to plan."

Sam said, "First stop, Hawaii?"

"Sounds good to me," Dean replied. "Toes in the sand, matching shirts, drinks with umbrellas in them, sign me up."

Castiel smirked, "We'll have to take a plane to get there, Dean."

Dean replied, "Already got that solved. We're going to take a cruise."

Castiel responded, "I do have to point out that statistically speaking air travel is much safer than ship travel."

Dean snorted, "Never tell me the odds."

"As you wish, buttercup."

**Author's Note:**

> Fear not, there are two more stories coming after to wrap up the loose ends and to fix those things that are still broken.


End file.
